In the United States v. Mississippi Valley Generating Co., 1960, the Supreme Court ruled on a case involving alleged fraud in a contract between private companies and the federal government for construction of a power plant. The government claimed that it had been defrauded by false statements made during negotiations, which led to an inflated price being paid for electricity generated by the plant. The defendants argued that they were immune from prosecution because their actions were part of official duties under contracts with governmental agencies. However, the court held that immunity did not extend to contractors who commit fraud against the government while performing contractual obligations. Therefore, even though these individuals acted as agents of governmental bodies when executing contracts or making purchases on behalf of those entities, they could still be held liable if they engaged in fraudulent activities detrimental to public interest.

In the dissenting opinion for United States v. Mississippi Valley Generating Co., Justice Harlan argued that the majority's decision to allow a lawsuit against a private company, based on alleged fraud in its contract with the federal government, was an overreach of judicial authority. He contended that such matters should be left to Congress and administrative agencies who have more expertise in handling contractual disputes involving public funds. Furthermore, he expressed concern about potential negative impacts on future business transactions with the government if companies fear they could face lawsuits years after contracts are signed. He also disagreed with the majority's interpretation of "property" under RICO (Racketeer Influenced and Corrupt Organizations Act), arguing it should not include intangible rights like those involved in this case.